Hydraulic quick-acting safety device.



C. R. PRATT.

HYDRAULIC QUICK ACTING SAFETY DEVICE. APPLICATION FILED nmzs, I910.

1,182,301 1 Patented May 9, 1916.

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THE COLUMBIA PLANOGRAPH co., WAsmNumN, n. c.

C. R. PRATT.

HYDRAULIC QUICK ACTING SAFETY DEVICE.

APPLICATION FILED APR. 23. 1910.

1, 182,31 1. Patented May 9, 1916.

3 SHEETSSHEET 2.

i i/Woman: 3/ 5' :4 l z g w w a lflimueaa THE COLUMBIA PLANOGRAPH ,C0.. WASHINGTON, n. c.

C. R. PRATT.

HYDRAULIC QUICK ACTING SAFETY DEVICE.

APPLICATION FILED APR.23. 1910. 1,182,531 1. Patented May 9, 1916.

3 SHEETS-SHEET 3 7 wmvssszs MBIA PLANOGRAPH co., WASHINGTDN, n. x

UNITED STATES PATENT OFFICE.

CHARLES R. PRATT, 0F MONTCLAIR, NEW JERSEY, ASSIGNOR T0 OTIS ELEVATOR COMPANY, OF JERSEY CITY, NEW JERSEY, A CORPORATION OF NEW JERSEY.

HYDRAULIC QUICK-ACTING SAFETY DEVICE.

Specification of Letters Patent.

Patented May 9, 1916.

Application filed April 23, 1910. Serial No. 557,284.

To all whom it may concern Be it known that I, CHARLES R. PRATT, a citizen of the United States, residing at Montclair, in the county of Essex and State of New Jersey, have invented a new and useful Improvement in Hydraulic Quick- Acting Safety Devices, of which the following is a specification.

This invention relates to safety devices for elevators, and more particularly to such safety devices as have jaws located on the car and which are adapted to grip guide rails in the hoistway.

One of the objects of the invention is to provide means to bring the jaws quickly and initially to the gripping position, and then powerfully to apply the jaws to the guide rails to stop the car.

A further object is to provide variable fluid means for initially applying the gripping jaws to the rails and then to apply the jaws to the rails with increasing pressure.

Another object is to provide means actuated manually from the car or automatically from without the car, either independently or in conjunction, to set the gripping jaws, and other means completely to apply the jaws to stop the car.

A still further object is to combine resilient means for quickly and initially placing the jaws in gripping position and powerful mechanical means for further increasing the gripping action of the jaws.

Other objects of my invention will appear hereinafter, the novel combinations of elements being pointed out in the appended claims.

In the elevator art it is desirable to employ a safety device which shall be not only absolutely positive in action and practice but also it should permit of such flexibility and elasticity that there will be no dangerous shocks or strains upon the apparatus when the car is stopped. This combination of fluid and mechanical means for initially and finally applying the gripping jaws to the rails presents a means for obviating these dangers. In the complete application of the jaws to the rails there is suflicient leakage and resilience in the fluid devices to prevent the harsh and unnecessary grinding action of a too sudden stop.

Referring more particularly to the drawings, Figure 1 represents an elevator provided with my safety device located under the elevator car; Fig. 2 is a detail view, partly in section of the same; Fig. 3 is a plan view partly in section showing the arrangement of my invention; and Fig. 4 is a part sectional elevation similar to Fig. 2 with a modified form of fluid pressure generating device.

The elevator car may be raised and lowered in any convenient manner. Fig. 1 shows an elevator car C, its motor M, brake B, driving mechanism D, counterweight WV, and the rope 10 which passes about the traction drum 1. The safety mechanism is located under the car C and has the hand lever 13 in the car for manual operation and the rope 8 connected to the governor rope 2 for automatic operation. The automatic operation is effected by means of the governor rope 2 and the automatic speed governor 5. The governor rope 2 has the yielding connection 7 with the car and passes around the governor sheave 4 and the weighted sheave 3. The governor 5 is adapted to operate the governor rope gripping devices 6, 6 to grip the governor rope 2 when the speed of the elevator car exceeds a predetermined limit, thereby pulling on the rope 8, since the car C is moving with respect to the governor rope Q, and applying the safety device to stop the car.

A more detailed description of the safety device shown by Figs. 2 and 3 will now be given. In Fig. 3 only one of the rail gripping devices is shown since the other would be similar and symmetrically located. The jaws J are adapted to grip the guide rail 12. The initial application of the jaws is effected by means of the fluid pressure devices H, and further application by the rotation of drum 11. Pressure for operating the devices H is generated in the cylinders G and K, the former of which is operated by means of the rope 8 and the sheave F which has connection with the rod 23, and the latter of which is operable from within the elevator car by means of the lever 13. lVhen pressure is generated in these cylinders G and K, the pressure is conveyed to the devices H by means of the conductors 31 and 15, and single way valves 16, 16' are provided to prevent the reduction of pressure therein. When pressure is admitted through the valves 16 or 16 the piston 10 remains stationary and the cylinder moves outwardly carrying with it the adjusting screw 19, the block 20, and imparting motion to the jaws J through the links 5], 9' sufficient to bring the jaws into gripping position or even lightly to apply them to the rail 12. The pipes 15 and 31 are sufficiently elastic to accommodate themselves to the movement of the cylinder. The piston rod 17 is surrounded by the coil spring 24 which is adapted to provide resilient means for opposing the initial application of the jaws and automatic means for returning the cylinder to normal position when the release cock 2:) (preferably located in the car) is opened. The holes in the periphery of the drum 11 are provided for the insertion of a bar to rotate and reset the drum in its normal position.

The piston rod 17 is threaded to corre spend with the threaded block 18 connected with the drum 11; when the drum is operatively rotated the piston rod 17 is moved outwardly carrying with it the cylinder and applying the gripping jaws J with increasing pressure, subject to the leakage of the fluid device. The valves 16, 16', prevent the reduction of pressure in the fluid device H so the motion imparted to the gripping jaws by the rotation of the drum is transmitted through the said fluid device.

The automatic pressure generating device comprises the piston 9 movable within the cylinder G and attached to the rod 23. The pulley sheave F is supported by the arms 27 which are suitably mounted on the supports 29 by means of the bearings 23, and the arms 22 make connection between the rod 23 and the sheave arms 27. The springs 32 are adapted to return the sheave F and the piston 9 to the normal position after being operated. hen the governor operates and the rope 3 is pulled the pressure thus produced on the sheave F causes the arms 22 to swing on their pivots and carry the sheave F toward the winding drum 11. The piston 9 is thus moved to the right and pressure is generated in the cylinder G which pressure is eonnuunicated to the fluid devices H to effect the initial and quick application of the gripping jaws J to the rails. In this portion of the apparatus there is sufficient leakage between the piston 9 and the cylinder G to permit the resetting of the piston by means of the springs 32.

The pressure device manually operable from the elevator car comprises a cylinder K, a piston 21 movable therein. a stop collar 26 within the cylinder to limit the downward movement of the piston, and a piston rod 14 adapted to slide through the piston 21 and having a collar 34 secured to it to provide a bearing head for one end of the spring 30, the other end of which presses against the piston 21. The piston rod 14 extends upwardly and is provided with a hand lever 13 in the car. The cylinder K is also provided with a number of valves; valve 35 permits the admission of a fluid above the piston 21; the. return pipe 37 with the release valve 38 in the car provides a means for releasing the pressure above the piston 21; the inlet conductor 39 is provided with a one-way valve 40 to permit ingress of the fluid to the cylinder K, and the pop valve 141 permits the egress of the fluid under pressure by way of the conductor 15 to the fluid devices H. The fluid employed in this device as well as in the automatically operated pressure cylinder G may be either air or liquid as the use of either or both is contemplated in this connection, and for the latter substance it is necessary to provide the supply chamber T and the conductors 36 and 39 therefor. In order that the operation of this manual fluid pressure device may be more readily understood, the operation in the present connection will be set forth. Fig. 2 shows the normal position of the apparatus; to operate the piston the hand lever 13 is turned down, thereby forcing the piston rod 14 down. Since the piston 21 is not secured to the piston rod 14 it does not fall immediately but is acted upon by the spring 30 which forces it down. The pop valve 41 opens to release the generated pressure by way of conductor 15 which leads to the pressure operative devices H. The piston 21 comes to a stop when it reaches the collar 26 and is locked in such position by the automatic closure of the valve 35; it is thus seen that the initial pressure applied to the devices H is automatic. To increase the said pressure the piston rod 14 is moved up and down by means of the hand lever 13 in the car, fluid entering the cylinder K by means of the valve 40 and leaving by way of the valve 41. As the piston 21 is now held stationary, each downward stroke of the rod 14 forces through the pipe 15 an amount of fluid equivalent to the volume of that portion of the rod 14 which is projected below the piston 21. It is evident that by this means a very great pressure may be exerted upon the fluid pressure device H by way of the conductor 15, and the gripping jaws J may be applied with increasing pressure. This means of applying the increased pressure is slower than the application thereof by means of the drum 11, but it may be readily accomplished in this manner. It is also evident that this device may be used in connection with the automatic pressure generating device, or independently of it. To release the pressure above the piston 21 the release cock 38 is pressed and the piston may be drawn up by the piston rod 14. By means of this manual device and the re lease cook 25 (Fig. 3) the gripping jaws may be eased off and again applied to bring the car to rest at a given floor, when for instance the elevator car has been stopped between floors.

A modification of the fluid pressure generating device operable from within the elevator car is shown by Fig. 4 in which the cylinder K is provided with supply ports 42. 43. and exhaust ports H, 45 and the pop valve L. A piston I is connected by means of a rod 14' to a lever 13'. The downward movement of the piston forces a comparatively large volume of fluid under low pressure to actuate the fluid operative devices H and apply the gripping jaws initially and quickly to the rails; the up stroke of the piston P owing to the comparatiy'ely small effective area of the upper side of the piston. forces a smaller volume of fluid under the increasing pressure to effect further operation of the said device II, thereby increasing the pressure of the jaws against the rails. Owing to the comparatively small volume displaced by the upward stroke of the piston, the leverage is correspondingly increased, permitting the lever 13' to be moved upward against the increasing fluid pressure. The pop valve L limits the pressure applied to the devices H upon the first stroke and limits the pressure opposing the downward stroke of the lever 13. The other parts are the same as shown by Fig. 2, the operation of which has been described.

From the preceding description it is evident that the gripping jaws may be brought to the rails or lightly applied by an operator within the elevator car: that the initial pressure may be varied, and independent of the operator's attention or manipulation; and that the application of the jaws may be increased after the initial application thereof, by the operator in the car. W hen the speed of the car reaches a prescribed limit, the automatic governor effects the operation of the automatic pressure generating device and the rotation of the governor rope drum. It is evident that the manual pressure gen erating device may be operated simultaneously with the automatic generating device to apply the jaws, the drum and screw device operating thereafter completely to apply the jaws to the rails. Resetting of the devices is accomplished by manual or automatic means as set forth in the description.

The employment of fluid devices in connection with mechanical devices for applying an elevator safety device presents the advantages of resilience and flexibility in the operation thereof, for the reason that the leakage in the fluid device prevents a hard mechanical application which is both detrimental to the apparatus and unpleasant for the occupants of the car. and it also permits the smooth, steady, and sure operation of the safety device to bring the car to rest.

Although I have thus specifically described my invention and the preferred application thereof it is evident that the fluid devices may be either for pneumatic or hy draulic pressure. Furthermore I wish not to be limited to the precise construction, combination and arrangement of the several parts as herein set forth, as it is evident that those skilled in the arts to which my apparatus appertains, may make various changes without departing from the spirit and scope of the invention.

IVhat I claim and desire to secure by Letters Patent of the United States is 1. An elevator safety device comprising retarding means, fluid operated means for automatically applying the retarding means lightly, and additional manually operated fluid means for increasing the strength of application thereof.

In an elevator car safety device, the combination of retarding mechanism, fluid means operated from the car for effecting the initial application of the said mechanism, and additional means independent of the first named means for automatically completing the application thereof.

3. In an elevator car safety device, the combination of safety mechanism, fluid means operated from the car for effecting the initial application of the said mechanism, and automatic means independent of fluid pressure thereafter operative to stop the car.

1. In an elevator car safety device, the combination of safety mechanism, fluid means operated from the car and automatic means operated from without the car for effecting the initial application of the safety mechanism, and automatic means independent of fluid pressure for completing the application of the said mechanism.

In an elevator car safety device, the combination of safety mechanism, automatic fluid means operated from without the -ar for effecting the initial application of the safety mechanism, and automatic means for completing the application of the safety mechanism.

6. In an elevator car safety device, the combination of retarding mechanism, fluid pressure generating means on the car, pressure operated means for applying the said mechanism, and means for applying additional pressure to said mechanism.

7. In an elex'ator car safety device, the combination of safety mechanism, an automatic pressure generating device on the car, a pressure operated device for applying the safety mechanism, and automatic means for increasing the application of said mechanism to stop the car.

8. In an elevator car safety device, the combination of safety mechanism, automatic fluid pressure generating means on the car, means actuated thereby initially to apply the safety mechanism, and means subsequently operable to effect the complete application of said mechanism to stop the car.

9. In an elevator car safety device, the combination of retarding mechanism, fluid pressure generating means operated from within the car, means operated thereby to apply the retarding mechanism, and means thereafter operative to complete the application of the retarding mechanism and stop the car.

10. In an elevator car safety device, the combination of retarding mechanism, fluid pressure generating means operated from within the car and automatically from without the car, means dependent for actuation upon the generated pressure and operative when actuated to effect the application of the said retarding mechanism.

11. In an elevator car safety device, the combination of retarding mechanism, fluid pressure generating means operated from within the car and automatically from without the car, fluid means actuated thereby initially to apply the retarding mechanism, and automatic means for con'ipleting the ap plication thereof to stop the car.

12. In an elevator car safety device, the combination of retarding mechanism, fluid pressure generating means, an automatic governor, and means controlled thereby for actuating the said generating means and for acting in conjunction therewith to apply the said retarding mechanism.

13. In an elevator car safety device, the combination with fluid pressure generating means, of fluid pressure responsive means, and automatic means controlled by the speed of the car for actuating the generating means and for combining with the responsive means to stop the car.

1-1. In an elevator car safety device, the combination of retarding mechanism, fluid pressure generating and fluid pressure responsive means, automatic means for bringing the said generating means into operation when the car speed becomes excessive. and for acting in conjunction with the said responsive means initially to apply the retarding mechanism and subsequently to increase the pressure of application thereof.

15. In an elevator car safety device, the combination with retarding mechanism, fluid pressure generating and fluid pressure responsive means, of means in the car and automatic means for actuating said generating means, and a rotatable device to act in conjunction with the said responsive means for first lightly applying the retarding mechanism and subsequently completing the application thereof to stop the car.

16. In an elevator car safety device, the combination of retarding mechanism, automatically operated fluid-pressure generating means, and fluid-pressure generating means manually operable from the car, and fluid pressure responsive means for automatically applying the retarding mechanism.

17. In an elevator car safetv device, the combination of retarding mechanism, automatically operated fluid-pressure generating means, and fluid pressure generating means manually operable from the car, fluid pressure responsive means automatically operated by the pressure generating means to apply the retarding mechanism, and a mechanical device complementing the application thereof.

18. In an elevator car safety device com prising rail gripping aws, the combination of fluid means automatically and manually operable to apply the jaws, and additional automatic means to effect a complete application thereof independent of fluid pressure.

19. In an elevator car safety device comprising rail gripping jaws, the combination of automatic and manual fluid pressure generating means, a fluid operated device for applying the gripping jaws, and means dependent upon the speed of the elevator car for increasing the application thereof.

20. In an elevator car safety device, the combination of retarding mechanism, fluid pressure generating devices, a fluid respon sive device for applying the retarding mechanism, means to allow ingress and to prevent egress of the fluid from the said responsive device in applying the retarding mechanism, and means for effecting a more complete application of the retarding mechanism to stop the car.

21. In an elevator car safety device, the combination of retarding means, cylinders in which pressure is generated, a device quickly and initially operative to lightly apply the retarding means when such pressure is generated, and an automatic drum device to apply the retarding means more powerfully to stop the car.

22. In an elevator car safety device comprising rail gripping jaws, the combination of a cylinder and piston for effecting quick initial application of the jaws, an automatic fluid pressure generating device and a manually operable fluid pressure device to supply fluid pressure to the said piston, and means actuated conjointly with the said automatic means to effect stronger application of the gripping jaws.

In an elevator car safety device comprising rail gripping aws, the combination of a cylinder and piston for effecting quick initial application of the jaws, a fluid pressure generating device operable from the car for supplying fluid under pressure to the said cylinder, means for preventing the reduction of pressure in the said cylinder in applying the jaws, a rotatable drum operable when rotated more powerfully to apply the gripping jaws, and an automatic governor device for causing the said drum to rotate when the speed of the car exceeds a predetermined limit.

24. In an elevator car safety device comprising rail gripping jaws, the combination of fluid pressure generating devices, a cylinder and piston acted upon by the fluid under pressure, the cylinder being primarily movable with respect to the piston and operable thereupon lightly to apply the jaws and means thereafter operable to move both cylinder and piston to effect a stronger application of the jaws.

25. In an elevator car safety device comprising rail gripping aws, the combination of a fluid pressure generating device, a fluid pressure device operative when subject to the pressure of the generating device to apply the jaws, a rotatable drum operative when rotated to further apply the jaws through the said fluid pressure device, and an automatic governor operative to effect the operation of the generating device and the rotation of the said drum.

26. In an elevator car safety device comprising rail gripping jaws, the combination of a fluid pressure generating device, a fluid pressure device operative when subject to the pressure of the generating device to apply the jaws, a rotatable drum operative when rotated to further apply the aws through the said fluid pressure device, and an automatic governor operative to effect both operation of the generating device and the rotation of the drum after the generating device is operated.

27. In an elevator car safety device, the combination of retarding mechanism, a fluid pressure device operative to apply the said mechanism, an automatic fluid pressure generating device and a fluid pressure generating device operable from the car both and either operative to supply fluid pressure to the device which applies the said retarding mechanism.

28. In an elevator car safety dev1ce comprising rail gripping jaws, the combination of a fluid pressure device, automatic and manual means for effecting the operation of the said device lightly to apply the jaws, and a right and left screw device automatically operative to effect a further application of the gripping aws to stop the car.

29. In an elevator car safety device, the combination of safety mechanism, fluid means initially and quickly operable lightly to apply the safety mechanism, automatic means and manual means in the car for supplying fluid under pressure to the safety applying means, and a right and left screw device automatically operable to apply the safety mechanism with increasing pressure.

30. In an elevator car safety device, the combination of safety mechanism, fluid pressure operated means for operating said mechanism, and fluid pressure generating apparatus therefor comprising means for generating low pressure and means for generating high pressure.

31. In an elevator car safety device, the combination of fluid pressure operative means, and a device therefor operating upon excessive car speed to supply a large volume of fluid under lower pressure to said means, and means thereafter to increase the pressure of said fluid to apply the safety device with increased pressure.

In an elevator car safety device comprising rail gripping aws, the combination of fluid pressure means to operate the jaws, and fluid pressure generating apparatus comprising means to supply a large volume of fluid under light pressure initially to operate the said jaws and to supply a smaller volume of fluid under increased pressure completely to operate the rail gripping jaws.

33. In an elevator ear safety device, the combination of friction members operable by fluid pressure to retard the motion of the car, and means inoperative while the car operates at normal speed and automatically operated by the motion of the car when it has attained a prescribed limit to generate fluid pressure to actuate the said friction members.

34. In an elevator car safety device, the combination of friction members to retard the motion of the car, fluid means to actuate the friction members, and a fluid pressure generator to supply a large volume of fluid at low pressure and then to supply a smaller volume at higher pressure to the said fluid means.

In an elevator, the combination of a car, guide rails, gripping jaws, means to apply fluid pressure to bring the said jaws up to the guide rails, a speed governor controlling said means, and means to automatically increase said pressure sufliciently to powerfully applv the gripping jaws to the guide rails.

36. In an elevator, the combination of a car, guide rails, gripping jaws, a speed governor, a governor rope, means operated by said rope for generating fluid pressure, mechanism operated by said fluid pressure for moving the said jaws up to the guide rails, and means for increasing said fluid pressure and thereby powerfully applying the gripping jaws.

37. In an elevator, the combination of a car, guide rails, gripping jaws, a fluid device for operating the gripping jaws, a governor, a governor rope, means operated by said rope for generating fluid pressure, and means for conveying the generated pressure to said fluid operating device.

38. In an elevator, the combination of a car, guide rails, gripping jaws, a governor, a governor rope, mechanism operated by said rope for generating fluid pressure, means for transmitting said pressure to the jaws to move them up to the guide rails, a safety drum operated by the governor rope, and means operated by said drum to powerfully apply the gripping jaws to the guide rails.

39. In an elevator, the combination of a car, retarding mechanism carried thereby, a fluid motor for operating said mechanism, manual means in the car for generating fluid pressure to operate the motor, and means controlled by the speed of the car for automatically supplying fluid pressure to the said motor.

In testimony whereof, I have signed my name to this specification in the presence of two subscribing Witnesses.

CHARLES R. PRATT.

\Vitnesses:

JAMES HODGE, RUssELL M. EVERETT.

Gopie: of this patent may be obtained for five cents each, by addressing the "Commissioner of Patents, Washington, D. C. 

